All contact information has been condensed to the left of the page, to make room for an activity stream. That activity stream is now at the core of the contact detail page.
The activity stream now shows you:
If and when contact information was updated.
Notes, from yourself or teammembers.
Email campaigns, with tracking reports. You’ll be able to see whether someone clicked, and what specifically they clicked on.
Replies and other email conversations with your contacts.